Practical physicistDavid MacKay

A physicist and Professor of Engineering at the University of Cambridge, MacKay grew tired of the debate about energy. Declaring he intended to cut “U.K. emissions of twaddle,” he wrote a book applying pure reason and mathematics (shunning emotional “self-righteousness” and “greenwashing”) to the sustainable energy debate. “I was tired of the debate,” he explained. “The extremism, the nimbyism, the hairshirt. We need a constructive conversation about energy, not a Punch and Judy show.” The result, published in 2009, was Sustainable Energy — Without the Hot Air. The book was released first — for free — online, where it was downloaded 400,000 times, but it still quickly sold more than 40,000 copies in print. In the book, MacKay pointed out that energy was energy: a constantly lit 40 watt lightbulb, for instance, consumed one kilowatt hour per day, while a typical car driven 50km/day consumed 40 kWh/d of energy. It didn’t matter whether the energy involved came from burning gasoline, or was electricity made by photovoltaic panels, because in the end it was simply energy used to do a job. Thus, MacKay decried such meaningless “eco-gestures” as unplugging mobile phone chargers, pointing out that “The amount of energy saved by switching off the phone charger is exactly the same as the energy used by driving an average car for one second.” That makes unplugging the charger the equivalent of “bailing out the Titanic with a teaspoon.”

That doesn’t mean nothing should be done, however. MacKay argued that it was rational to adopt sustainable energy, since oil and gas are finite resources that should be reserved for things only they can do. Yet the amount of space required to produce solar, wind, biomass, wave-power, or other renewable generation facilities is a daunting prospect. “Such an immense panelling of the countryside and filling of British seas with wind farms may be possible according to the laws of physics, but would the public accept and pay for such arrangements?” he wrote. “If the answer is no, we are forced to conclude that current consumption will never be met by British renewables. We require either a radical reduction in consumption, or significant additional sources of energy — or, of course, both.” Such as: “‘Turn your thermostat down’ is, by my reckoning, the single best piece of advice you can give someone. So is ‘fly less’ and ‘drive less’.” MacKay’s thoughtful, realistic scientific approach to the issue led to him being appointed to a five-year term as the chief scientific adviser to the U.K.’s Department of Energy and Climate Change, and he was elected a Fellow of the Royal Society in 2009. Sir David MacKay (he was knighted this year) died April 14, from stomach cancer. He was 48.